| 摘要 |
PURPOSE:To synthesize a chrominance carrier signal from a point sequential color signal train and to simplify a matrix circuit 21, by limiting the band of the three primary color signals from a chrominance carrier frequency applied to an LPF of the specified characteristics and performing point sequential processing of the signal into the point sequential chrominance signal. CONSTITUTION:The three primary color signals R, G, B are applied to the matrix circuit 21 for the specified matrix operation to output four kinds of chrominance signals C1-C4. The signals C1-C4 are applied to LPFs 22-25 having the characteristics of H0(omega) being 1/2fsc or below the chrominance carrier frequency fsc, and the band of the signals C1-C4 is limited. The band- limited chrominance signals C1-C4 are applied to a signal selection circuit 26 to form the point sequential chrominance signal train taking 1/fsc as the period with point sequential processing. This signal train is applied to a BPF27 having the H1(omega) filter characteristics of the center frequency fsc to extract the 1st sampling carrier of the signal train, to synthesize the chrominance carrier signal having the band of H0(omega-omegasc)XH1(omega), the result is outputted to a signal output terminal 28 and the circuit 21 is simplified. |
